Polyphenylene oxide-recycled polystyrene composition and method

ABSTRACT

A polymer composition comprises a melt compounded product of a polyphenylene oxide polymer and a recycled polystyrene material. The recycled polystyrene material exhibits a melt flow index greater than about 25 when devolatized by heating above its glass transition temperature. The polymer composition may be in various forms including extruded pellets, extruded foam, and expandable foam beads.

This is a division of application Ser. No. 07/478,099, filed Feb. 12,1990.

FIELD OF THE INVENTION

The present invention relates to polymer compositions comprising apolyphenylene oxide polymer and a recycled polystyrene material. Moreparticularly, the present invention relates to such compositionsprepared by melt compounding a polyphenylene oxide polymer and arecycled polystyrene material, and to methods for preparation of suchcompositions.

BACKGROUND OF THE INVENTION

Polystyrene foam materials are well known in the art. A summary ofpolystyrene and related thermoplastic foams is disclosed by Ingram etal. in Plastic Foams, Part II, Chapter 10, edited by Frisch et al.,Marcel Dekker, Inc., New York (1973) Extruded low-density foam articlescomprising a mixture of polystyrene and polyphenylene oxide are alsoknown in the art as demonstrated by the Allen et al. U.S. Pat. No.4,857,390, the Krutchen et al. U.S. Pat. Nos. 4,535,100, 4,598,100 and4,532,263, and German Reference No. DE 3220856. The Park U.S. Pat. Nos.4,661,302, 4,705,811 and 4,734,441 additionally disclose the use ofpolyphenylene oxide to enhance the melt strength of expanded polystyrenefoam board during post expansion processes.

Polystyrene materials are used in numerous industrial and consumerapplications. In view of the great amount of polystyrene materialsappearing in waste refuse, it is desirable to recycle post-usepolystyrene materials for reuse. One type of polystyrene material whichhas been successfully recycled for reuse comprises polystyrene foam andsolid materials which have been employed in food packaging, for example,in fast food restaurants. In one process, the used polystyrene materialis sorted by hand, washed, devolatized, ground and extruded into pelletsto provide a recycled material having a melt flow index of between 3 and4 g/10 min (ASTM D-1238, Condition G). The recycled material has beenused to produce injection molded non-food contact products.

However, one type of polystyrene material which has not beensuccessfully recycled for further use comprises bromine-modifiedpolystyrene foams. The bromine-modified polystyrene foam materials arecommonly used in industrial packaging applications, for example,consumer electronics and appliances, and comprise about 60% of allpolystyrene waste refuse. The bromine modifiers are, for example,compounds containing aliphatic, cycloaliphatic and aromatic bromine, andare originally included in the polystyrene foams in order to improvetheir processability and to serve as flame retardants for the foammaterials. However, the bromine-containing compounds have relatively lowthermal stability. Thus, when the bromine-modified polystyrene foammaterials are heated, the bromine-containing modifiers thermallydecompose. The decomposition products react with the polystyrene tocause large reductions of molecular weight, resulting in a nonusableproduct. Heating of the bromine-modified polystyrene foams above theirglass transition temperatures causes devolatization of the foammaterials and provides products having a melt flow index greater thanabout 25, and oftentimes having a melt flow index greater than about100. In view of the high melt flow index of this material, such productswere heretofore believed unsuitable for further practical use.

Thus, a need exists for further advances in the development and use ofpost-consumer polystyrene materials.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to providecompositions and methods employing recycled polystyrene materials. It isa more specific object of the invention to provide compositions andmethods which successfully employ recycled polystyrene materials derivedfrom bromine-modified polystyrene foams. It is an additional object ofthe present invention to provide compositions which include recycledpolystyrene material and which may be in the form of extruded foamproducts or expanded foam beads suitable for use in variousapplications. It is an additional object of the invention to providepolymer compositions containing recycled polystyrene material, whichcompositions exhibit an advantageous combination of physical properties.It is a further object of the invention to provide methods for preparingsuch compositions.

These and additional objects are provided by the compositions andmethods according to the present invention. More particularly, thepolymer compositions of the present invention comprise a melt compoundedproduct of a polyphenylene oxide polymer and a recycled polystyrenematerial. In a more specific embodiment of the invention, the recycledpolystyrene material comprises bromine-modified polystyrene foam andexhibits a melt flow index greater than about 25 when devolatized byheating above its glass transition temperature. While the recycledpolystyrene material alone is not capable of being processed in aplasticating extruder using conventional melt compounding techniques,the compositions according to the present invention comprising thepolyphenylene oxide polymer and the recycled polystyrene material may beprocessed in a plasticating extruder using conventional melt compoundingtechniques. The polymer compositions of the invention may be prepared invarious forms, for example, as extruded foam or as expanded foam beads,suitable for use in a variety of applications.

These and additional objects and advantages will be further apparent inview of the following detailed description.

DETAILED DESCRIPTION

The polymer compositions according to the present invention comprise amelt compounded product of a polyphenylene oxide polymer and a recycledpolystyrene material. While the recycled polystyrene material isgenerally not processable in a plasticating extruder using conventionalmelt compounding techniques, the combination of the polyphenylene oxidepolymer and the recycled polystyrene material provides a mixture whichmay be melt compounded using conventional plasticating extruderapparatus.

Polyphenylene oxide polymers adapted for use in the polymer compositionsof the present invention comprise polymers and copolymers havingrepeated structural units of the following general formula: ##STR1##wherein each R individually represents a monovalent substituent such ashydrogen, halogen, alkyl, aryl, alkoxy and other hydrocarbon groups, ris from 1 to 4 and n represents the degree of polymerization.Preferably, n is at least 20, and more preferably, n is at least 50.

The polyphenylene oxide polymers suitable for use in the polymercompositions of the present invention are well known in the art and maybe prepared by any of a number of processes known in the art fromcorresponding phenols or reactive derivatives thereof. Examples ofpolyphenylene ether resins and methods for their production are setforth in the Hay U.S. Pat. Nos. 3,306,874 and 3,306,875 and in theStamatoff U.S. Pat. Nos. 3,257,357 and 3,257,358, all of which areincorporated herein by reference. Throughout the Specification andClaims the term "polyphenylene oxide polymer" includes unsubstitutedpolyphenylene oxide polymers, substituted polyphenylene oxide polymersand polyphenylene oxide copolymers.

Preferred polyphenylene oxide polymers adapted for use in the polymercompositions of the present invention include, but are not limited to,poly(2,6-dimethyl-1,4-phenylene)ether;poly(2,3,6-trimethyl-1,4-phenylene) ether;poly(2,6-diethyl-1,4-phenylene)ether;poly(2-methyl-6-ethyl-1,4-phenylene)ether;poly(2-methyl-6-propyl-1,4-phenylene)ether;poly(2,6-dipropyl-1,4-phenylene)ether; poly( 2-ethyl-6-propyl-1,4-phenylene)ether; poly(2,6-dilauryl-1,4-phenylene)ether;poly(2,6-diphenyl-1,4-phenylene)ether;poly(2,6-dimethoxy-1,4-phenylene)ether; poly(2,6-diethoxy-1,4-phenylene)ether;poly(2-methoxy-6-ethoxy-1,4-phenylene)ether;poly(2-ethyl-6-stearyloxy-1,4-phenylene)ether;poly(2,6-dichloro-1,4-phenylene)ether;poly(2-methyl-6-phenyl-1,4-phenylene)ether;poly(2,6-dibenzyl-1,4-phenylene)ether;poly(2-ethoxy-1,4-phenylene)ether; poly(2-chloro-1,4-phenylene)ether;poly(2,6-dibromo-1,4-phenylene)ether; copolymers thereof, and the like.Particularly preferred polyphenylene oxide polymers for use in thecompositions of the present invention includepoly(2,6-dimethyl-1,4-phenylene) ether,poly(2,3,6-trimethyl-1,4-phenylene)ether, and blends of or copolymersincluding units of 2,3,6-trimethyl-1,4-phenylene ether and units of2,6-dimethyl-1,4-phenylene ether. Examples of such polymers andcopolymers are set forth in U.S. Pat. No. 4,806,297.

The polymer compositions of the present invention also include arecycled polystyrene material. In the present specification and claims,the term "recycled" refers to polystyrene material which has served itsintended use and would otherwise be discarded as waste refuse.Preferably, the recycled polystyrene material is derived frombromine-modified polystyrene foam which is well known in the art andexhibits a melt flow index greater than about 25 when devolatized byheating above its glass transition temperature. Generally,bromine-modified polystyrene foam contains bromine compounds havingrelatively low thermal stability. The bromine compounds improve theprocessability of the polystyrene foam materials and also serve as flameretardants. The polystyrene foam materials may also include additionalsynergistic flame retardants, for example, organic peroxide compoundssuch as dicumyl peroxide, and nucleating agents which also exhibit lowthermal stability. The polystyrene materials are generally amorphous,and when devolatized by heating above their glass transitiontemperature, the materials exhibit a significant increase in their meltflow index. Generally, when devolatized by heating above their glasstransition temperature, the bromine-modified polystyrene foam materialsexhibit melt flow indices greater than about 25, 50 or even 100.Throughout the present specification and claims, reference to melt flowindex refers to the property measured according to ASTM D-1238,Condition G (200° C., 5 kg). The high melt flow indices exhibited bythese materials upon devolatization by heating above their glasstransition temperature indicate that the bromine-modified polystyrenefoam materials are not processable according to conventional meltcompounding techniques.

However, in accordance with the present invention, when the recycledpolystyrene material is combined with a polyphenylene oxide, theresulting mixture may be melt compounded using conventional techniquesto provide a polymer composition product suitable for use in variousforms and in various applications.

The recycled polystyrene material which is combined with thepolyphenylene oxide polymer may comprise various forms ofbromine-modified polystyrene foam which is either devolatized by heatingabove its glass transition temperature prior to melt compounding withthe polyphenylene oxide polymer or is devolatized by heating above itsglass transition temperature during the melt compounding process. Forexample, the bromine-modified polystyrene foam may comprisebromine-modified polystyrene extruded foam, bromine-modified expandedpolystyrene foam beads, or the like.

The polyphenylene oxide is included in the polymer compositions of theinvention in an amount sufficient to improve the rheological propertiesof the recycled polystyrene material. More specifically, thepolyphenylene oxide is included in the polymer compositions in an amountsufficient to render the recycled polystyrene material processable in aplasticating extruder. Preferably, the polymer compositions of theinvention comprise at least about 20 weight percent of the polyphenyleneoxide, based on the polyphenylene oxide and the recycled polystyrenematerial. More preferably, the compositions comprise from about 35 toabout 80 weight percent of the polyphenylene oxide and from about 65 toabout 20 weight percent of the recycled polystyrene material, based onthe polyphenylene oxide and the recycled polystyrene material.

The polymer compositions of the present invention may further includeadditional components. For example, the compositions may include asecond polystyrene resin which is different from the recycledpolystyrene material. The second polystyrene resin may be anypolystyrene known in the art, including but not limited to polystyrenehomopolymers, halogenated polystyrenes, styrene-maleic anhydridecopolymers, rubber modified polystyrenes,acrylonitrile-butadiene-styrene copolymers, styrene-acrylonitrilecopolymers, poly-alphamethylstyrene polymers, and mixtures thereof.

Additionally, the polymer compositions of the invention may contain oneor more conventional additives known in the art. Such additives include,among others, reinforcing agents and fillers, plasticizers, impactmodifiers, flame retardants, lubricants, colorants, thermal stabilizers,light stabilizers, antistatic agents and the like.

The polymer compositions of the invention are prepared by meltcompounding the polyphenylene oxide polymer and the recycled polystyrenematerial. As described above, the recycled polystyrene material maycomprise bromine-modified polystyrene foam which has been devolatized byheating above its glass transition temperature prior to melt compoundingwith the polyphenylene oxide polymer. The bromine-modified polystyrenefoam may be in the form of polystyrene extruded foam, expandedpolystyrene foam beads, or the like. Alternatively, the recycledpolystyrene material may be devolatized by heating above its glasstransition temperature during the melt compounding process. In thisembodiment, wherein the recycled polystyrene material is devolatizedduring the melt compounding process, it is advantageous that therecycled polystyrene material is in the form of a granulated foam.Additionally, it may be advantageous to pressure compact the recycledpolystyrene material either before or after granulation.

Subsequent to melt compounding, the polymer compositions of theinvention may be further processed into various forms depending on thedesired application of the compositions. For example, the meltcompounded product may be formed into an extruded cellular foam forvarious applications in the automotive industry and/or the building andconstruction industry, including automotive headliners, insulation, wallpanels, curtain wall and flooring. In a preferred embodiment, thepolymer compositions of the invention are formed into low densityextruded cellular foams having a density in the range of from about 1.0to about 30 lb/ft³. The cellular foams may be formed using conventionalfoam extrusion methods and apparatus. Suitable blowing agents for use inpreparing the cellular foams comprise halogenated hydrocarbons, forexample the Freon® chlorofluorocarbon compounds, and/or non-halogenatedhydrocarbons including, for example, pentane, and/or other blowingagents known in the art.

Additionally, the polymer compositions of the present inventioncomprising the melt compounded product may be granulated or pelletizedfor further use. For example, the melt compounded product may be formedinto micropellets or granulated into small particles to form expandablefoam beads. Such beads may be formed by imbibing the micropellets orsmall particles with a suitable blowing agent, for example, ahalogenated hydrocarbon such as a Freon® compound, a non-halogenatedhydrocarbon blowing agent, for example pentane, or any other blowingagent known in the art. The resulting expandable imbibed beads may beexpanded, and the resulting expanded beads may be fused into a foamedarticle in accordance with methods well known in the art.

The compositions according to the present invention may also be employedin the formation of various articles using any conventionalthermoplastic forming technique, including, among others, injectionmolding, compression molding, blow molding, structural foam molding,sheet or profile extrusion, and the like.

The compositions and methods according to the present invention areillustrated by the following examples.

EXAMPLE 1

This example demonstrates the preparation of a polymer compositionaccording to the present invention. The recycled polystyrene materialemployed in this composition comprised a bromine-modified expandedpolystyrene material which had been devolatized by heating above itsglass transition temperature. The recycled polystyrene had a melt flowindex greater than 100 and was in the form of a granulated material. Thepolyphenylene oxide polymer employed in this composition exhibited anintrinsic viscosity of 0.40 dl/g (in chloroform at 25° C.). Thecomposition was prepared from 50 weight percent of the polyphenyleneoxide polymer and 50 weight percent of the recycled polystyrenematerial. The composition was made on a Werner-Pleiderer 53 mm twinscrew extruder at 325 rpm using a throughput rate of 250 to 280 lbs/hr.A vacuum of 23 inches Hg was applied at barrel 10 of the apparatus toaid in devolatization. The resulting extrudate had a measuredtemperature ranging from about 574° to 577° F. and was cooled in waterand pelletized.

EXAMPLE 2

This example demonstrates the preparation of an extruded low densityfoam board using the melt compounded product of Example 1. Specifically,the foam board was prepared from 50 weight percent of the meltcompounded product of Example 1 and 50 weight percent of additionalrecycled polystyrene material designated PA105 and supplied by PlasticsAgain, Inc. of Leominster, Mass. The PA105 material was derived from therecycle of non-bromine containing polystyrene. Freon-12® was used as theblowing agent in an amount of 13.5 lb/hr. The foam extrusion was carriedout on an Egan tandem 2.5-inch/3.5-inch diameter single screw extruderfoam line fitted with board forming and take-off equipment. Theresulting foam board had an approximate width of 70 cm and anapproximate thickness of 4 cm. The board was characterized for density,cell dimensions in the machine (x-axis), cross-machine (y-axis), andvertical (z-axis) directions according to ASTM D-3576 and percent opencells using a Beckman Model 930 air comparison pycnometer at threeequidistant points across the board width designated A, B and C, 30 daysafter manufacture (30 D.A.M.) Additionally, 30 days after manufacture,the center of the foam board (position B) was subjected to measurementof selected physical properties. Specifically, the softening temperaturewas determined using a modified Vicat procedure in which a rectanglularsample measuring approximately 3/16 inch in depth, 1/2 inch in width and1 inch in length was placed under an applied strss of 21.3 psi by a 3/8inch diameter steel cylinder. The modified Vicat softening temperatureis defined as that temperature at which the sample deflects 1 mm whilebeing heated at 2° C./min in a circulating oil bath. The compressionstrength was measured on 3 inch square foam blocks at 0.1 inch/mincrosshead speed using an Instron Model 1125 universal testing machineinterfaced with a Series IX computerized data acquisition and analysissystem. The flexural stress at 5% deflection and modulus were alsomeasured on the Instron tester. The flex test was carried out on 3 inchby 12 inch specimens (10 inch span) cut to a 1 inch thickness. Thecrosshead speed was 0.02 in/min. Each sample was tested with the uncutsurface positioned on the tension side of the flexural beam. The resultsof these measurements are set forth in Table I.

                  TABLE I                                                         ______________________________________                                        PROPERTIES 30 D.A.M.                                                                         A        B      C                                              ______________________________________                                        Density (lb/ft.sup.3)                                                                          2.59       2.59   2.59                                       Average          2.56                                                         % Open Cells     9.3        9.7    9.7                                        Average          9.6                                                          Cell Dimensions (mm):                                                         (ASTM D-3576)                                                                 x-axis           0.97       0.70   0.61                                       y-axis           0.70       0.70   0.61                                       z-axis           0.70       0.61   0.54                                       Average          0.79       0.67   0.59                                       Grand Average    0.68                                                         Modified Vicat Softening                                                                            238.9  (1.6)                                            Temperature (21.3 psi,                                                        1 mm deflection), °F.:                                                 Compression Strength (psi)                                                                          33.3   (5.0)                                            @ 10% Deformation                                                             Flexural Stress at 5%                                                         Deflection (psi):                                                             Machine Direction     60.9   (4.2)                                            Cross Machine Direction                                                                             64.7   (4.0)                                            Flexural Modulus (psi):                                                       Machine Direction     2860   (570)                                            Cross Machine Direction                                                                             2730   (320)                                            ______________________________________                                         NOTE: () indicate standard deviation values.                             

EXAMPLE 3

In this example, an extruded low density foam board was preparedgenerally in accordance with the method described in Example 2. The foamboard of this example was prepared from a composition comprising 50parts by weight of the melt compounded product from Example 1 and 50parts by weight virgin polystyrene comprising Dylene™ 8,80 supplied byArco Chemical Co. Additionally, a nucleant comprising 40% Mistron ZSCtalc concentrate was added in the amount of 1.4 parts per hundred partsby weight resin. The Freon-12® blowing agent was employed in an amountof 13.3 lb/hr. The overall appearance of the foam board resulting fromthis example was indistinguishable from a foam board prepared accordingto a similar method using a composition comprising 25 weight percentpolyphenylene oxide and 75 weight percent virgin polystyrene. Apredominantly closed-cell sample and a 45% open-cell sample of the foamboard of this example were also subjected to measurement of theproperties described in Example 2, at 30 DAM. The results of thesemeasurements are set forth in Table 2.

                  TABLE II                                                        ______________________________________                                        PROPERTIES 30 D.A.M.                                                                       (Closed Cell)                                                                            (Open Cell)                                                        A    B      C      A    B    C                                   ______________________________________                                        Density (lb/ft.sup.3)                                                                        3.27   3.17   3.18 3.17 3.14 3.30                              Average        3.21               3.20                                        % Open Cells   6.7    3.5    3.2  51.5 40.8 44.0                              Average        4.5                45.4                                        Cell Dimensions (mm):                                                         ASTM D-3576)                                                                  x-axis         0.23   0.27   0.24 0.27 0.26 0.27                              y-axis         0.26   0.27   0.24 0.30 0.29 0.29                              z-axis         0.30   0.32   0.32 0.35 0.37 0.32                              Average        0.26   0.29   0.27 0.31 0.31 0.29                              Grand Average  0.27               0.30                                        Modified Vicat Softening                                                                       247.4  (1.7)     246.7                                                                              (2.2)                                  Temperature (21.3 psi,                                                        1 mm deflation), °F.:                                                  Compression Strength                                                                           91.9   (8.6)     83.7 (8.3)                                  (psi) @ 10% Deformation                                                       Flexural Stress at 5%                                                         Deflection (psi):                                                             Machine Direction                                                                              64.1   (10.3)    71.4 (0.9)                                  Cross Machine Direction                                                                        96.7   (34.8)    74.6 (3.4)                                  Flexural Modulus (psi):                                                       Machine Direction                                                                              2360   (420)     2770 (140)                                  Cross Machine Direction                                                                        4050   (780)     3870 (320)                                  ______________________________________                                         NOTE: () indicate standard deviation values.                             

The results set forth in Table I and Table II demonstrate that cellularfoam products prepared from the compositions according to the presentinvention exhibit good compressive and flexural properties.

EXAMPLE 4

This example demonstrates the preparation of expandable foam beads froma polymer composition according to the present invention. A mixture of3.4 kg of the recycled polystyrene material described in Example 1 andan equal quantity of powdered polyphenylene oxide polymer having anintrinsic viscosity of 0.46 dl/g (chloroform, 25° C.) was prepared in ahigh intensity Henschel mixer. The mixture was melt compounded using a30 mm Werner-Pleiderer twin screw extruder, extruded through a 15-strandmicrodie (approximately 0.040 inch hole diameters) and pelletized. Thefeed rate varied between about 10 and 35 lbs/hr while the extruderoperated at a constant 350 rpm. The melt temperature near the die wasmeasured at about 328° C.

The resulting "micropellets" were then imbibed with a blowing agent.More particularly, 75 g of the micropellets were sieved through a No. 16screen (14 mesh) and charged into a 300 ml reactor containing 150 mldeionized water, 1.2 g polyvinyl alcohol, and 9.6 g n-pentane. Thereactor was sealed and the contents were agitated at approximately 800rpm. The reactor was then heated to 95° C., maintained at thistemperature for 1 hour, heated to 135° C. and maintained at thistemperature for 4 hours. The reactor was then cooled to roomtemperature. As a result of this process, the substantially cylindricalmicropellets were transformed to substantially spherical imbibed beads.The imbibed beads were then washed with tap water, dried under ambientconditions and screened.

Small quantities of the imbibed beads were placed in a stainless steeltray and expanded in a hot air oven at 270°, 300° or 325° F. for aperiod of 2, 3 or 5 minutes. The bulk density of the resulting expandedbeads was then measured by weighing a prescribed volume in a graduatedcylinder. The results of these measurements are set forth in Table III.

                  TABLE III                                                       ______________________________________                                                   FOAM BEAD DENSITY (LB/FT.sup.3)                                    Oven Temp. (°F.)                                                                    2 min.      3 min.  5 min.                                       ______________________________________                                        270          8.1         7.1     6.2                                          300          4.7         4.3     --                                           325          3.3         2.7     --                                           ______________________________________                                    

Thus, the polymer compositions of the present invention comprising themelt compounded product are suitable for use in preparing expandablepolystyrene foam beads for use in various applications.

The preceding examples are set forth to illustrate specific embodimentsof the invention and are not intended to limit the scope of thecompositions and methods of the present invention. Additionalembodiments and advantages within the scope of the claimed inventionwill be apparent to one of ordinary skill in the art.

What is claimed is:
 1. A foamable polymer composition which comprises amelt-compounded product of (a) a polyphenylene oxide polymer; and (b) arecycled polystyrene material, wherein the recycled polystyrene materialcomprises bromine-modified polystyrene foam which exhibits a melt flowindex greater than about 25 when devolatized by heating above its glasstransition temperature; said composition further including (c) a blowingagent.
 2. The composition of claim 1, wherein the recycled polystyrenematerial comprises bromine-modified expanded polystyrene foam beadswhich have been devolatized by heating above their glass transitiontemperature.
 3. An extruded cellular foam composition which comprises amelt-compounded product of (a) a polyphenylene oxide polymers and (b) arecycled polystyrene material which has been bromine-modified and whichexhibits a melt flow index greater than about 25 when devolatized byheating above its glass transition temperature.
 4. A polymer compositionas defined by claim 3, wherein the cellular foam has a density in therange of from about 1.0 to 30 lb/ft³.
 5. A polymer composition, in thefoam of expandable foam beads, which comprises a melt-compounded productof(a) a polyphenylene oxide polymer; and (b) a recycled polystyrenematerial which has been bromine-modified and which exhibits a melt flowindex greater than about 25 when devolatized by heating above its glasstransition temperature.
 6. The polymer composition of claim 1, whereincomponent (a) comprises:i) poly(2,6-dimethyl-1,4-phenylene) ether; ii)poly(2,3,6-trimethyl-1,4-phenylene) ether; or iii) a blend or copolymerwhich includes units of 2,6-dimethyl-1,4-phenylene ether and units of2,3,6-trimethyl-1,4-phenylene ether.
 7. The polymer composition of claim1, further including a second polystyrene resin which is different fromthe recycled polystyrene material.
 8. The composition of claim 7,wherein the second polystyrene resin is selected from the groupconsisting of polystyrene homopolymers, halogenated polystyrenes,styene-maleic anhydride copolymers, rubber-modified polystyrenes,acrylonitrile-butadiene-styrene copolymers, styrene-acrylonitrilecopolymers, poly-alpha-methylstyrenes, and mixtures of any of theforegoing.
 9. The composition of claim 1, further including at least oneadditive selected from the group consisting of reinforcing agents,fillers, plasticizers, impact modifiers, flame retardants, lubricants,colorant thermal stabilizers, light stabilizers, and antistatic agent.10. The composition of claim 3, further including a second polystyreneresin which is different from the recycled polystyrene material.
 11. Thecomposition of claim 3, further including at least one additive selectedfrom the group consisting of reinforcing agents, fillers, plasticizers,impact modifiers, flame retardants, lubricants, colorants, thermalstabilizers, light stabilizers, and antistatic agents.
 12. Thecomposition of claim 5, wherein component (a) comprises:i)poly(2,6-dimethyl-1,4-phenylene) ether; ii)poly(2,3,6-trimethyl-1,4-phenylene) ether; or iii) a blend or copolymerwhich includes units of 2,6-dimethyl-1,4-phenylene ether and units of2,3,6-trimethyl-1,4-phenylene ether.
 13. The composition of claim 5,further including a second polystyrene resin which is different from therecycled polystyrene material.
 14. The composition of claim 13, whereinthe second polystyrene resin is selected from the group consisting ofpolystyrene homopolymers, halogenated polystyrene, styrene-maleicanhydride copolymers, rubber-modified polystyrenes,acrylonitrile-butadiene-styrene copolymers, styrene-acrylonitrilecopolymers, poly-alpha-methylstyrenes, and mixtures of any of theforegoing.